The difference between PVC, PC, and PET as thin film switches

Thin film switches are a widely used input interface in electronic devices. They are usually composed of multiple layers of materials, among which the most common three plastic materials are polyvinyl chloride (PVC), polycarbonate (PC), and polyethylene terephthalate (PET). These materials each have their own advantages and disadvantages, and are suitable for different application scenarios. The following is a detailed comparative analysis of these three materials: PVC (Polyvinyl Chloride) Advantages: Low cost: PVC is one of the cheapest materials, suitable for mass production. Chemical resistance: PVC has good corrosion resistance and oil resistance, and can resist the erosion of many chemicals. Flame retardant performance: PVC with added flame retardants can meet the fire protection requirements in some industry standards. Disadvantage: Environmental impact: The production and use of PVC involve the emission of toxic substances, and its degradation process may produce harmful substances. Poor flexibility: Unplasticized hard PVC has higher hardness, lacks elasticity, and is prone to breakage. Long term use issue: Prolonged exposure to ultraviolet radiation or high temperatures may cause PVC to age and become brittle. Advantages of PC (Polycarbonate): Mechanical strength: PC has high impact strength and stress cracking resistance, making it very sturdy and durable. Transparency: PC maintains a high transmittance, making the design more flexible. Heat resistance: PC has a high thermal deformation temperature and can operate over a wide temperature range. Disadvantage: High cost: Compared to other materials, PC is relatively expensive. Dimensional stability: PC’s dimensional stability at extreme temperatures is not as good as other materials. Processing difficulty: PC requires specific molds and processes for processing, which increases manufacturing costs. Advantages of PET (Polyethylene Terephhalate): Lightweight: PET is lightweight, making it an advantage for mobile devices and portable products. Weather resistance: PET has excellent outdoor weather resistance and is not easily affected by ultraviolet rays and moisture. Electrical performance: PET has good electrical insulation performance and is suitable for use in thin film switches in electrical equipment. Disadvantage: Wear resistance: Compared with PVC and PC, uncoated PET has poor wear resistance and requires additional coating treatment to improve its service life. Rigidity: The rigidity of pure PET may lead to the risk of creases or fractures during use. The choice of material depends on the specific usage environment and requirements. For example, if cost sensitive and does not require complex shapes or special functions, PVC may be the best choice; If it is a high-end device that requires transparency and durability, then PC may be a better choice; PET is competitive in outdoor equipment and applications that require excellent electrical insulation performance. In practical applications, different materials are often combined together to obtain the desired characteristics, such as using PVC substrate and covering it with a layer of PET protective film.